Modern aircraft, particularly airliners, have various sensors to monitor the condition and performance of aircraft components including brakes, wheels and tyres. Typically, each monitored parameter (e.g. brake temperature, tyre pressure, wheel speed, etc.) may be measured by a separate sensor, and the sensor data provided to a dedicated monitoring system for that parameter. If a monitored parameter deviates from a normal operating range, the associated monitoring system may generate an alert.
A deviation from normal of a single parameter cannot provide much information about the root cause of the deviation. Therefore, in response to such an alert, a maintenance crew must perform comprehensive investigations in order to identify the location and nature of the fault. Such investigations are time consuming and may cause a significant interruption to the operation of the aircraft. Moreover, in some cases it may turn out that the fault is sufficiently minor that the aircraft can keep operating until its next scheduled maintenance operation, in which case the interruption was unnecessary.
There also exists a trend toward actively controlling various aircraft systems and components, such as braking systems, for example to optimize performance or increase operational lifespan. Such active control may alter the operation of an aircraft system based on feedback from the sensors monitoring the components of that system. Where such active control is operating to alter the behaviour of a given aircraft component, any deviation from normal behaviour of the component may not be detectable based on the sensor data relating to the performance of that component, since the active control system may automatically compensate for the deviation. Various faults could therefore become undetectable by current monitoring systems, as a result of active control being introduced.
An improved system for detecting faults relating to aircraft systems, and in particular aircraft braking systems, is therefore desired.